Revert "Merge branch 'horse/gke-aws-auth' into 'master'"

What does this MR do?

Reverts https://gitlab.com/gitlab-org/quality/gitlab-environment-toolkit/-/merge_requests/302 as it breaks non Hybrid AWS environments due to the code not being able to be made optional as the provider block doesn't accept count.

module.gitlab_ref_arch_aws.data.aws_eks_cluster.gitlab_cluster_for_provider: Still reading... [13m30s elapsed]
╷
│ Error: error reading EKS Cluster (gitlab-qa-10k-services): couldn't find resource
│
│   with module.gitlab_ref_arch_aws.data.aws_eks_cluster.gitlab_cluster_for_provider,
│   on line 35, in data "aws_eks_cluster" "gitlab_cluster_for_provider":
│   35: data "aws_eks_cluster" "gitlab_cluster_for_provider" {
│

Related issues

Relates https://gitlab.com/gitlab-org/quality/gitlab-environment-toolkit/-/issues/216

Author's checklist

When ready for review, the Author applies the workflowready for review label:

• Merge request:
  • Corresponding Issue raised and reviewed by the GET maintainers team.
  • Merge Request Title and Description are up to date, accurate, and descriptive
  • MR targeting the appropriate branch
  • MR has a green pipeline
• Code:
  • Check the area changed works as expected. Consider testing it in different environment sizes (1k,3k,10k,etc.).
  • Documentation created/updated in the same MR.
  • If this MR adds an optional configuration - check that all permutations continue to work.
  • For Terraform changes: setup a previous version environment, then run a terraform plan with your new changes and ensure nothing will be destroyed. If anything will be destroyed and this can't be avoided please add a comment to the current MR.
• Create any follow-up issue(s) to support the new feature across other supported cloud providers or advanced configurations. Create 1 issue for each provider/configuration. Contact the Quality Enablement team if unsure.